d = {'Michael': 95, 'Bob': 75, 'Tracy': 85}
print(d['Michael'])

d['Adam'] = 17
print(d['Adam'])

print('Thomas' in d)

print(d.get('Thomas'))
print(d.get('Thomas', -1))

print(d)
d.pop('Bob')
print(d)

s= set([1, 2, 3])
print(s)
s.add(4)
print(s)
s.remove(3)
print(s)

s2 = {2, 3, 4}
print(s & s2)
print(s | s2)